Revert of Disallow posting tasks to SequencedWorkerPools by default.

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index 9226d7dc8af67ffcc4c2b93e12dc56c4835ed12f..9caaf4124250991d1c91b5228c3198feda141e74 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -1209,8 +1209,7 @@
   // IOThread's initialization which happens in BrowserProcess:PreCreateThreads.
   SetupFieldTrials();
 
-  // Initializing TaskScheduler and enabling SequencedWorkerPool needs to be
-  // here for the following reasons:
+  // Task Scheduler initialization needs to be here for the following reasons:
   //   * After |SetupFieldTrials()|: Initialization uses variations.
   //   * Before |SetupMetrics()|: |SetupMetrics()| uses the blocking pool. The
   //         Task Scheduler must do any necessary redirection before then.